Field of the Invention
This invention relates to non-volatile storage systems and, more particularly, to controlling access to non-volatile storage systems.
Description of the Related Art
In a typical processing application (e.g., an automotive application) a non-volatile memory (NVM) may be implemented in a stand-alone memory integrated circuit or may be embedded within other integrated circuits. The NVM is used to store information, such as boot instructions, configuration information (e.g., operational parameters or information related to security and access), or other types of information, that are accessed and used by a microcontroller or other processing circuit to perform various operations. To protect the integrity of that information, e.g., to prevent unauthorized software execution or attack by malware, a manufacturer may control access to the information stored in the NVM of a product. A user (e.g., a microcontroller or other control circuit of the associated system) may have limited or no access to the information unless the user or subsystem in communication with the user authenticates the contents of the NVM before providing access to the contents of the NVM. A security processor or other control logic calculates a message authentication code or secure hash based on an image retrieved from memory and compares that message authentication code or secure hash to a value stored in secure memory (i.e., tamper-proof memory). However, calculating a message authentication code or secure hash for a large image may take a substantial amount of time that exceeds the start-up requirements for a system in some applications. Accordingly, improved techniques for controlling access to information are desired.
The use of the same reference symbols in different drawings indicates similar or identical items.